The present invention is an improvement of the surgical device disclosed in my U.S. Pat. No. 4,465,065. It serves for connection of the fractured neck to the shaft of a femur by means of a pre-drilled connector plate, without the requirement of making a large incision in the overlying skin and tissue.
The connector plate according to the above patent and according to the present invention has a sharp lower edge by which it penetrates through a small incision in the trochanter region into close contact with the shaft. During the operation the plate is temporarily attach to the horizontal portion of a connector arm, while its vertical portion extends parallel to the plate and is provided with holes which are coaxial with the holes in the plate. Concentric guide tubes are inserted through the holes in the vertical portion of the connector arm, are pushed through the soft tissue up to the plate and serve as guides for pre-drilling of the bone parts in the correct position as viewed by X-ray equipment. After pre-drilling the inner guide tubes are removed and the outer tubes serve for insertion of long screws, and are afterwards removed. The long screws are tightened so as to contract the fractured parts. Short screws serving for firm attachment of the plate to the femur shaft are now inserted through the vertical portion, of the connector arm, after suitable drilling through tubes inserted into holes in the arm, which are, co-axial with the holes in the plate. The connector arm is now detached from the plate, and the wound is closed.
The present device is similar and serves the same purpose, but is designed to avoid certain drawbacks of the original device which have come to light during its use in operations of the kind referred to. The following main drawbacks were observed:
The long screws did not permit active compression of the fractured bone parts, a task which is most important for quick healing of the bone and for early use of the limb by the patient. PA1 The long screws were not sufficiently guided in the holes of the connector plate and were apt to wobble, often resulting in instability of the fracture after connection. PA1 The screws were apt to protrude out of the bone into the soft tissue, after walking of the patient had started and the fracture had been pressed. PA1 The connector plate was not firmly fastened to the femur during operation, which made drilling difficult. PA1 1. A connector plate of substantially rectangular cross section comprising a straight lower portion which has a sharpened lower end permitting it's insertion through a small incision in the skin and its being pushed through the soft tissue along the femur into its final position. Its upper end is short and bent outwardly to conform to the contour of the bone; it is perforated by a screw-threaded bore and at least one straight bore which serve for its connection to a holding tool. The upper part of the straight portion is perforated by two obliquely directed and screw-threaded bores, and the lower part is perforated by two or more straight, counter-sunk bores, all of which are used for guiding the drills for pre-drilling of the bone parts and for insertion of screws for firm attachment of the plate to the femur shaft and for connection of the fractured bone parts. PA1 2. Two long screws used for connecting the fractured parts to the connector plate have their outer ends firmly guided and lengthwise and rotatably movable in relatively short sleeves; they extend through the upper bores through the femur neck and are screwed into the head portion; The outer ends of the sleeves are firmly held in the screw-threads of the two upper bores of the plate, thereby keeping the screws in firm position, while permitting axial movement; the outer ends of the screws are recessed each comprising a coaxial recess of hexagonal or other polygonal cross section which is continued by a screw-threaded bore. The inner ends of the sleeves are slightly crimped preventing the screws from escaping out of the sleeves by contact with a step on the screws. PA1 3. Two or more short screws securing the lower plate portion to the femur shaft, having their heads hidden inside the counter-sinks. PA1 1. An angular connector arm, including a short horizontal portion for connection to the upper end of the connector plate and a longer vertical portion extending parallel to the direction of the connector plate; the vertical portion is perforated by two obliquely directed boresband by two or more straight bores, all of them coaxial with the bores of the connector plate, but of larger diameter, permitting the passage and fixation of guide tubes. It is preferably provided with set screws for locating the guide tubes and with means for attaching of an aiming device at its bottom end. The short horizontal portion is lengthwise perforated and contains a long screw and at least one protruding pin for engagement with the screw-threaded bore and the straight bore in the upper end of the connector plate. PA1 2. Two long composite guide tubes of a length sufficient to extend through the bores in the connector arm to the corresponding oblique bores in the connector plate; they include an outer tube of an inner diameter corresponding to the diameter of the screw to be inserted and to be screwed into the fractured neck, and two inner, removable tubes, viz. a first tube concentrically bored to the diameter of a guide wire to be pushed therethrough into the bone, and a second tube concentrically bored to the diameter of a drill adapted to drill the bone for reception of the two long screws. PA1 3. Two Or more shorter guide tubes for insertion into the straight bores in the connector arm up to the corresponding bores in the connector plate serving for predrilling bone before final insertion of the screws for firm attachment of the connector plate to the femur shaft. PA1 4. A special screw driver adapted for inserting and fixing the long screws and their sleeves in the connector plate and in the fractured bone parts, and for compressing the fracture after its connection.
The device according to the present invention aims to obviate these drawbacks by providing improved components which facilitate and shorten the progress of the operation on the one hand, and hold the fractured parts in full alignment and under compression after their complete jointing, on the other. In addition, sufficient space is provided for axial sliding out of the connecting screws, while preventing their protrusion out of the connector plate.